Apparatus for feeding mercury



a m March 9, 1943.

Original Filed Aug. 6, 1938 MERCU I In'v e ntor; Anthony J. Marshaus,

by Hm u His Attorney j Patented Mar. 9, 1943 S PATENT OFFICE APPARATUS FOR FEEDING MERCURY Anthony J. Marshaus, East Cleveland, Ohio, as-

signor to General Electric Company, a corporation of New York Application August {6, 1938, Serial No. 223,519

Renewed July 19, 1940 Claims.

My invention relates to apparatus for feeding .or dispensing mercury or similar substances, and more particularly to apparatus for introducing mercury or similar substances into electrical discharge lamps, tubes, rectifiers or other devices.

Because of the danger of contaminating or otherwise disturbing the controlled atmosphere in vapor electrical devices, care must be exerthe gases. If the vaporizable substance is introduced into the device after the atmosphere therein is finally established, difiiculty is experienced in measuring out the correct quantity of said substance and introducing it into the device without also introducing foreign matter thereinto*or without changing either the pressure or condition of the atmosphere therein.

An object of my invention is to provide an improved apparatus for dispensing small amounts of mercury or similar substances from a large quantity thereof. Another object is to provide apparatus for introducing a given quantity of a vaporizable substance into a vapor electrical device without affecting the atmosphere or introducing foreign matter therein. Still anotherv object is to provide apparatus for conveniently and economically introducing an accurately measured amount of vaporizable substance into a vapor electrical device. Other features and advantages of my invention will appear from the following description of a species thereof and from the accompanying drawing. I

The drawing is an elevation, in section, of apparatus comprising my invention.

Referring to the drawing, the dispensing apparatus Iii comprising my invention is shown mounted on an exhaust manifold II directly above an exhaust head I2 carrying a discharge lamp I3 into which the mercury or other vaporizable substance is to be introduced. The discharge lamp I3, comprising an envelope I3 having an electrode I4 located at each end thereof, is completely sealed except for the opening through the exhaust tube I4 which is gripped by the rubber washer I5 in the exhaust head I2. The washer I5 is compressed tightly around the exhaust tube by the upward pressure of a metal washer I6 against said washer I5. The washer I6 and the ball bearings I! in engagement therewith are moved upward by the cap I 8 which is threaded onto the exhaust head I2 and is turned by means of arm I 8, thereon to increase or release the pressure on the rubber washer I5. The exhaust head I2 is also provided with an insert 20 which has a tapered opening 20 serving the dual purpose of restricting the flow of gas to the exhaust manifold II and guiding the mercury released by the dispensing apparatus into the end of the exhaust tube I4.

The exhausting and gas filling of the discharge lamp I3. which preferably takes place prior to the placing of the mercury in said. discharge lamp I3, is brought about by conventional apparatus (not shown) connected to the exhaust manifold I I. Following this operation, the dispensing apparatus is operated and a stipulated amount of mercury is released thereby down through the manifold II, the insert 20 and the exhaust tube I4 to the lamp envelope I3. The mercury 2| is provided in a sufficient quantity in a reservoir comprising the cup 2-2 to supply a considerable number of discharge lamps I3. The said cup 22 is mounted directly on the exhaust manifold I I and is provided with a central discharge opening or conduit 23 through which the mercury 2I is normally prevented from flowing by the tube .or sleeve 24 and the tubular plunger or feed member 25. The tube 24 is attached directly to the cup 22 by a press fit although it might be formed integrally therewith. The tubular plunger 25, on the other hand, is slidable on said tube 24 and rests in the position shown during the inoperative periods of the apparatus. During said inoperative periods, the mercury 2| flows into a small aperture or recess 26 in the side Wall of the hollow plunger 25. During operation of the apparatus, the said plunger 25 is moved upward so that said aperture 26 is carried above the upper end of the tube 24. A jarring of the hollow plunger 25 at the end of its upward movementdislodges the mercury which drops down through the tapered opening 24 in said tube 24 and through passage 23 in the cup 22 to the exhaust manifold I I.

The movement of the hollow plunger 25 upward to the discharge position is brought about in this particular instance by the magnetic attraction of the field of a coil or electro-magnet nut 33.

which is clamped to the upper end of the bell housing 3| at the desired position by the screw 32. The bell housing 3| is made from aluminum or other substantially non-magnetic material so that the function of the coil 21 is not interfered with and covers the open top of the cup 22 to which it is attached by the knurled compression The nut 33 engages the flange 34 on the bell housing 3| through the ball bearings 35 and washer 36 and presses said flanges against the rubber washer 31 which hermetically seals said bell housing to the cup 22. Since the aluminum of the bell housing 3| would form an amalgam with mercury, said bell housing 3| is protected by a coating 38 of platinum fused to the inner surface thereof.

The particular quantity of mercury discharged each time the apparatus is operated de ends on the size and number of the apertures 26 in the lower end of the hollow plunger 25, although the particular amount of mercury fed to the discharge lamp |3 can be made up by the repeated operation of the apparatus. In this particular instance only one aperture 26, which is .052 inch in diameter, is used to feed seventeen milligrams of mercury to the discharge lamp l3 in one operating period of the apparatus. The upward movement of the hollow plunger 25 carries the aperture therein up beyond the lower edge of the floating sleeve member 39 which separates or shears the small quantity of mercury in said aperture from the main mercury body 2| and also carries the flange 40 on the lower end of the plunger against said sleeve 39 which is then caused to move upward therewith. The movement of the hollow plunger 25 continues until the head of the piston 28 strikes the dome of the bell housing 3| at which time the aperture 26 in said plunger 25 is located above the upper edge of the tube 24. The jarring of piston 28 28. The coil 21 is mounted on the split collar If desired, the exhaust head I 2 and thedispensing apparatus In of my invention can be joined together in another manner providing some connection is provided thereto for the exhausting and gas filling of the lamp l3. Such an assembly can be mounted at the periphery of a rotatable turret like that provided by the convenand plunger 25 causes the mercury within the aperture 26 to fall into the interior of said plunger 25. The freed body of mercury is caught by the tapered opening 24' in tube 24 and directed thereby to the central opening 23 in the cup 22, thence through manifold ll, insert 20 and exhaust tube |4 in'to envelope l3. The sleeve 39 moves down as the level of the mercury 2| recedes but it may be modified so as to be fastened to either the cup 22 or the bell housing 3| and it may,be made longer so that it will function in the manner desired. If the sleeve 39 1s modifled so as to remain at one position at all times, the flange 40 on the end of the hollow plunger 25 must be removed to allow the plunger to move upward as desired.

To avoid pressure and atmospheric differences between the exhaust manifold and the. interior of the cup 22, wherein the mercury. is contained, the hollow plunger 25 is provided with a plurality of apertures 42 which allow the free circulation of the gases therebetween and which are always above the level of said mercury 2|. As shown, any misalignment of hollow plunger 25 and the piston 28 with reference to the bell housing 3| is taken care of by the ball and socket joint at 43 between said piston and said hollow plunger. The longitudinal grooves 45 in the sides of the piston 28 allow the gas to escape from behind said piston during its upward movement. The return movement of the plunger 25 is brought about by the combined weight of said plunger and the piston 28 when the switch 29 is opened.

tional exhaust machine and can be operated by one or more coils 21 located at spaced positions about said turret and temporarily brought into operating relation to the dispenser.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. Apparatus for dispensing measured amounts of mercury or similar substances comprising a cup portion adapted to hold a quantity of the mercury, a hollow tubular member having an aperture in the wall thereof normally located within said quantity of mercury, closure means within said tubular member normally closing off said aperture to prevent escape of the mercury therethrough, another closure means at the outer side of said tubular member extending into said quantity of mercury and normally spaced from said aperture; and means for causing a relative movement between said tubular member and said two closure means, said parts being constructed and arranged to first cause said second-mentioned closure means to close off said aperture at the outer side of said tubular member while said aperture is within said quantity of mercury and to then cause said aperture to be uncovered by said first-mentioned closure means to permit the mercury within said aperture to drop into the interior of said tubular member.

2. Apparatus for dispensing measured amounts of mercury or similar substances comprising a cup portion adapted to hold a quantity of the mercury and. having a discharge passage in the bottom thereof, a tube extending upwardly from the bottom of said cup in alignment with said passage, a tubular plunger slidably surrounding said tube and having an aperture in the wall thereof adjacent its lower end, said aperture being normally within the quantity of mercury in said cup, and means for moving said plunger upward to carry the said aperture therein above the upper end of said tube to cause the mercury carried up in-said aperture to be discharged into the interior of said plunger and thence downward through said tube and said cup passage.

3. Apparatus for dispensing measured amounts of mercury or similar substances comprising a cup portion adapted to hold a quantity of the mergury and having a discharge passage in the bottom thereof, a tube extending upwardly from the bottom of said cup in alignment with said passage, a tubular plunger slidably surrounding said tube and having an aperture in the wall thereof adjacent its lower end, said aperture being normally within the quantity of mercury in said cup, a sleeve surrounding said plunger and arranged to extend upwardly beyond the upper surface of said quantity of mercury and also beyond the upper end of said tube and means for moving said plunger upward to carry the said aperture therein above the upper end of said tube to cause the mercury carried up in said aperture to be discharged into the interior of said plunger and thence downward through'said tube and said cup passage.

4. Apparatus for dispensing measured amounts of mercury or similar substances comprising a cup portion adapted to hold a quantity of the mercury and having a discharge passage in the bottom thereof, a tube extending upwardly from the bottom of said cup in alignment with said passage, a reciprocable tubular plunger closely and slidably surounding said tube and having an aperture in the wall thereof adjacent its lower end, said aperture being normally within "the quantity of mercury in said cup and being closed off at the interior side of said plunger by said tube, a sleeve member closely surrounding said plunger above said aperture therein and arranged to extend upwardly beyond the upper surface of said mercury and also beyond the upper end of said tube whereby upward movement of said plunger causes a quantity of mercury to be trapped in said aperture between said sleeve member and tube and then carried above the upper end of said tube where it is discharged into the interior of said plunger and drops downward through said tube and said cup passage.

5. A mercury feeding apparatus for an electrical device having an exhaust tube. said apparatus comprising a resilient connection between said exhaust tube and exhaust apparatus. an upwardly extending conduit in line with said exhaust tube, said upwardly extending conduit communicating with a member provid ng a recess sufiicient tohold a predetermined small quantity of mercury, a mercury reservoir in contact with said member and in position to fill said recess with mercury. and a second member to shear from the first member any mercury other than of mercury, a mercury reservoir in contact with said member and in position to fill said recess with mercury; and a second member to shear from the first member any mercury other than that in the recess, said first member being capable of dropping the mercury held in its recess into the upwardly extending conduit when moved sufliciently.

9. A mercury feeding apparatus for an electrical device having an exhaust tube, said apparatus comprising connection means for making that in the recess, said first member being capable of dropping the mercury held in its recess into the upwardly extending conduit when moved sufilciently.

6. The combination set forth in claim 5 wherein the upwardly extending conduit is in communication with the top of the mercury reservoir so that the pressure in said conduit and reservoir is equalized.

'l. A mercury feeding apparatus for an electrical device having an exhaust tube. said apparatus comprising an exhaust head having means for making a resilient air-tight connection to said exhaust tube. a hermetically sealed mercury reservoir above said' exhaust head, a conduit extending downward from said reservoir in line with said exhaust tube and being in communication with the top of said reservoir so that the pressure in said conduit and reservoir is equaliced, a member adjacent said conduit having a recess suiilcient to hold a predetermined small quantity of mercury. said member being normally in a position such that its recess is filled with mercury from said reservoir, and a second member arranged to shear from the first member any an air-tight connection between said exhaust tube and exhaust apparatus, a mercury reservoir above said connection means, a conduit extending downward from said reservoir in line with said exhaust tube, a member in said reservoir having a recess sufiicient to hold a predetermined small quantity of mercury, said member being normally in a position such that its recess is filled with mercury from said reservoir, and a second member arranged to shear from the first member any mercury otherthan that in the recess, said first member being capable of dropping the mercury held in its recess into the said conduit when moved sumclently.

10. In combination, exhaust apparatus comprising mea'ns for making air-tight connection with an exhaust tube extending upward from an envelope, and a mercury dispensing device 10- cated above said connection means comprising a mercury reservoir. a conduit extending upward from said connection means into the interior of said reservoir and terminating at a point above the level of the mercury in said reservoir. a feed member in said reservoir having an aperture therein adapted to hold a definite small amount of mercury, and means for raising said iced member to carry its apertured portion from a point within the mercury in the reservoir to a point above the upper end of said conduit to discharge the mercury held in said aperture into the conduit and thence downward therethrough and through said exhaust tube into said envelope.

ANTHONY J. MARSHAUS. 

